“IN TERMS OF …”

1. “IN TERMS OF …” DO NOW: take handout And begin to work on it

2. AIM: REGENTS REVIEW TOPIC 4 – MATTER DO NOW In M.C. packet Matter Questions

3. Matter is classified as a puresubstance or a mixture of substances • A substance has fixedcomposition and uniform properties throughout the sample (Ex. compounds and element) • A mixture is composed of two or more different substances that may be physically separated • A mixture may be homogeneous- (uniform – a solution) or heterogeneous(non uniform) • Substances in a mixture retain their original properties • Substances in a mixture may be separated by their size, polarity, density, boiling and freezing points, and solubility etc. • Filtration and distillation are examples of processes used to separate mixtures TOPIC 4 - MATTER REGENTS REVIEW S

4. REGENTS REVIEW- TOPIC 4 • An elementis a substance composed of atoms with the same atomic number. They cannot be broken down by chemical change • A compoundis two or more elements bonded together. Can only be broken down by chemical changes • Substances that form a compound gain new properties • The ratio of substances in a compound is fixed

5. REGENTS REVIEW- TOPIC 4 • A physical change is one that results in the rearrangement of existing particles in a substance (ex. freezing, boiling, etc.). A chemical change results in the formation of different substances with different properties • Chemical and physical changes can be exothermic or endothermic • The three phases of matter are solid, liquid, and gas. Each has its own properties • Solid have definite volume and shape. Particles are held in a rigid crystalline structure • Liquid have definite volume but no definite shape. Particles are mobile but still help together by strong attraction • Gasshave no definite volume or shape. They completely fill any closed container. Particles have largely broken free of the forces holding them together

6. REGENTS REVIEW- TOPIC 4 • A heating curve (cooling) traces the changes in temperature of a substance as it changes from solid to liquid to gas (or gas to liquid to solid) • When the substance undergoes a phase change there is no change in temperature There is a flat line until the change is complete. • When a phase change is occurring the potential energyof the substance changes while kinetic energyremains the same • As temperature increases, kinetic energy increases

7. REGENTS REVIEW- TOPIC 4 • Heat of fusions (Hf) is the energy needed to convert one gram of a substance from solid to liquid (clue melting) • Heat of vaporization (HV) is the energy needed to convert one gram of a substance from a liquid to a gas • Specific Heat (C) is the energy required to raise one gram of a substance 1 degree (Celsius or Kelvin) • Table Bspecific heat of water:

8. REGENTS REVIEW- TOPIC 4 • The combined gas law states the relationship between pressure, temperature , and volume of a sample of gas • Increasing pressure causes a decrease in volume (inverse) • Increasing temperature causes an increasein volume (direct) • Increasing temperature causes an increase in pressure (direct) • An ideal gas model is used to explain the behavior of gases. A real gas is most like an ideal gas when it is at low pressure, high temperature (PLIGHT!!!)

9. REGENTS REVIEW- TOPIC 4 • The Kinetic Molecular Theory (KMT) for an ideal gas states that all gas particles are: • Random straight line motion • Have no forces of attraction between them • Have negligible volume compared to the distances between them • Have no collisions that result in the transfer of energy from one particle to another, but there is no net loss of energy form the collision • Equal volumes of gases at the same temperature and pressure have an equal number of particles – avogadros hypothesis

10. REGENTS REVIEW- TOPIC 4 ENERGY • Energy can exist in different forms – chemical, electrical, electromagnetic, thermal, mechanical, nuclear • Stored energy – potential energy • Energy of motion – kinetic energy • The Law of Conservation of Energy states that energy can’t be created or destroyed but can change from one form to another

11. REGENTS REVIEW- TOPIC 4 • Heat is the transfer of energy (often but not always thermal energy) from a body of higher temperature to lower temperature • Temperature – measure of the average kinetic energy. Not a form of energy and should be not be confused with heat. • Concepts of kinetic and potential energy can be used to explain physical processes such as fusion (melting), solidification (freezing), vaporization (boiling, evaporation) condensation, sublimation, and deposition

12. REGENTS REVIEW- TOPIC 4 • Exothermic – energy is released. Typically causes the surrounding environment to become warmer • Endothermic energy is absorbed. Typically causes the surrounding environment to become colder

13. AIM: REGENTS REVIEW TOPIC 4 – MATTER Summary: answer questions in packet